Slide calculator



July 13, 1943. E. s. RUSSELL 2,323,937

Y I SLIDE CALCULATOR Filed Sept. 5, 1940 2 Sheets-Sheet 1 ATTO R N EYS July 13, 1943. 5 RUSSELL 2,323,937

SLIDE CALCULATOR Filed Sept. 3, 1940 2 Sheets-Sheet 2 INVENTOR wbea 7 ,4. ar/C ATTORNEYS; 3

Patented July 13, 1943 UNITED STATES PATENT OFFICE SLIDE OALCULATOR Emory S. Russell, Auburn, N. Y.

Application September 3, 1940, Serial No. 355,194

3 Claims.

graduated scales.

The calculator forming the subject of the invention is further directed to such a calculator made of cardboard or similar sheet material such as sheet cellulose or plastics, such as can be distributed to gasolene filling stations to assist the operators in determining the amount of anti-freeze compound needed to prevent the water in the cooling systems of various cars from freezing at a predetermined temperature, both on original fillings and also on additions to increase the protection, and it is therefore the principal object of the invention to provide a slide calculator made of sheet material which can be produced at very low cost, which is readily manipulated to give the exact information desired and which will stand up under conditions of severe and constant service without such wear as permits the cooperating scales to get out of line and thereby interfere with the ready operation of the calculator.

Another object is to provide such an inexpensive slide calculator made of sheet material in which there is a minimum of frictional resistance to the movement of the slide and in which the slide has adequate edge bearing surfaces against corresponding bearing surfaces on the supporting sheet so that there is no danger of the slide cutting itself free to an extent which will interfere with the operation of the calculator.

Another aim is to provide such a slide calculator made of sheet material which can be shipped as a flat sheet and in which the slide can readily be manipulated by a tab formed integrally with the slide and which can be bent up from the face of the calculator, this tab or fingerpiece also forming the stop for limiting the movement of the slide.

Another purpose is to provide such a calculator all parts of which can be made on commercial paper-forming machinery thereby to permit of large scale production of the calculators at very low cost.

Another purpose is to provide such a cardboard calculator in which the rear of the calculator is neatly covered by a paper backing sheet so that the only parts of the slide which are exposed are the manipulating tab and those parts of the slide visible through windows provided in the body sheet of the calculator, this backing sheet thereby insuring against accidental derangement of the slide.

In the accompanying drawings:

Fig. 1 is a front elevation of a slide calculator embodying my invention.

Fig. 2 is a vertical edge view thereof.

Fig. 3 is a horizontal section taken on line 3-3, Fig. 1.

Fig. 3a is a fragmentary enlarged horizontal transverse section, taken on line 3a--3a, Fig. 1.

Fig. 4 is a fragmentary rear view thereof showing a part of the backing sheet broken away to disclose the slide of the calculator.

Figs. 5, 6 and 7 are fragmentary sections taken on the correspondingly numbered lines of Fig. 1.

Fig. 8 is a diminutive view similar to Fig. l and showing a modified form of my invention.

Fig. 9 is a horizontal transverse section taken on line 9-9, Fig. 8.

Fig, 9a is an enlarged horizontal transverse section, taken on line 9a9a, Fig, 8.

Fig. 10 is a fragmentary perspective view of the obverse face of a calculator showing a further modified form of the invention.

The form of slide calculator shown in Figs. 1-7 comprises a body sheet It] made of heavy paper, cardboard, sheet cellulose or of a suitable plastic in sheet form and of generally rectangular form, this body sheet preferably having a hole II at its upper end by means of which it can be conveniently hung upon a wall. This body sheet is shown as having a considerably greater area than that necessary to support the slide of the calculator, this area being available for the printing of various tables and schedules which are useful in conjunction with the work for which the calculator is designed. The calculator shown was designed to calculate the amount of anti-freeze compound needed in automobile cooling systems to prevent freezing of the water at any predetermined subfreezing temperature, both for original fillings with the anti-freeze compound and also to increase the protection where an amount of anti-freeze is already present in the cooling water. However, the calculator obviously has a wide range of other uses and the invention is therefore not limited to any particular use of the calculator but is applicable generally where a low cost, accurate and frequently used calculator is required.

The slide l5 of the calculator is in the form of a generally rectangular sheet of heavy paper or cardboard and is arranged against the rear face of the body sheet It]. This slide I5 is shown as provided near its center with a semi-circular cut l6 so as to form a tab this tab being bent forwardly to project through a slot I8 provided centrally in the body sheet Ill. The tab forms a fingerpiece for moving the slide I5 up and down and is preferably bent to eX tend perpendicularly from the body sheet I0, although it can be folded fiat to facilitate ship-- ping the calculators as fiat sheets. The vertical movement of the slide i5 is determined by the length of the slot IS, the tab thereby forming a stop for limiting the movement of the" calculator.

The slide is guided in its vertical mcvemen so as to maintain accurate registry of the scales by means which provide extended bearing surfaces engaging the opposite vertical edges IQ of the slide so that there is no danger of the slide sawing its way out of register through constant use. At the same time the bearing means so provided have very little frictional resistance to the vertical movement of the slide so that the slide can readily be moved up and down through manipulating the fingerpiece IT.

For this purpose the body sheet I3 is shown as provided with four cutouts 20, each of which is of substantial longitudinal extent and the body sheet at the outer edges of the cutouts is also formed to provide a pair of outer, longitudinal edges 2| which are in vertical alinement with each other in a fore-and-a-ft plane and form bearing surfaces for the side edges of the slide. These straight edges 2! are spaced to accurately fit the longitudinal side edges IQ of the slide l5.

.To hold the opposite Vertical edges IQ of the slide in bearing engagement with the straight edges 2| of the cutouts 20, the body sheet I is provided at each of the cutouts 23 with a tab 25 which projects across the cutout and is formed from the body of the material in providing this cutout. Each of these tabs 25 is, however, substantially shorter in a longitudinal direction than the length of its cutout 20 so that the cutout extends.

a substantial distance both above and below the tab. The slide I is held against the rear face of the body sheet ID by the tabs 25 which hold the slide and body sheet in face to face contact with each other. In inserting the slide between the front faces of the tabs 25 and the rear face of the body sheet IS, the tabs 25 are displaced rearwardly and the portion of the body sheet i0 bounded by the tabs 25 may be displaced forwardly as best illustrated in Fig. 3a. The tabs,

however, remain substantially parallel with the back of the body member I0. This is due to the fact that the slide is necessarily of substantial thickness and its insertion under the tabs 25 require these tabs to be displaced to a plane in rear of the rear face of the body sheet I0, 1. e., to the plane of the rear face of the slide I5. This displacement of the tabs 25 rearwardly and the intermediate portion of the body sheet forwardly necessarily brings the vertical straight edges 2| of the cutouts 20 into edge to edge relation to the opposite vertical edges 19 of the slide l5, as best shown in Figs. 6 and 7. Since, however, these straight vertical edges 2| of the cutouts 20,

when viewed from the front, are in line with each other and in contact with the opposite vertical edges IQ of the slide, it will be seen that they squarely abut against the opposite vertical edges I9 of the slide and provide an edge-to-edge bearing between the slide and the body sheet. This opposing edge-to-edge bearing between the body sheet and the slide is a most important feature of the invention since by providing adequate bearing in this manner wear is avoided and the scales are maintained in correct register with the windows even after severe use of the calculator. Thus, this square edge-to-edge bearing of the edges I9 and 2| of the slide l5 and body sheet M, respectively, insures against the slide sawing its Way sidewise through the body sheet H) as it is continuously worked up and down and at the same time does not provide an undue amount of friction resisting vertical movement of the slide especially as compared with envelopes or the like which have been used to hold slides in slide calculators.

The body sheet II] is also shown as provided with a pair of Vertical windows 28 and 2.! which expose graduated scales 30 and 3| printed on the slide. These scales 30 and 3| are used conjointly with scales 32, 33, 34 and 35 printed on the body sheet ID at opposite sides of each of the windows 28, 29. The numerical figures determined by the adjustment of the slide in accordance with either of the scales 33 or 3| is visible through windows 36 and 3? provided in the body sheet l0 below the windows 28 and 29 respectively. It will be understood that the scales 30- 35 can be used independently or conjointly for many purposes and therefore no specific numerical scales have been illustrated in the drawings, the numerical figures of these scales being represented by dots applied to the lines of the scale.

In order to protect the back of the calculator and to completely conceal the back of the slide l5 and prevent accidental derangement thereof, the body sheet I0 is preferably provided with a backing sheet 38 which is cut evenly with the opposite vertical and horizontal straight edges of the body sheet Ill so as to provide, in effect, a single card or sheet. This backing sheet 38 is glued at its edges to the edges of the body sheet ID as indicated at 39 and may also be provided with additional vertical glue lines 40 adjacent the slide l5 if desired.

In the event additional calculating means are provided, a circular paper or cardboard disk 4| can be interposed between the body sheet l0 and the backing sheet 38 at the lower end of the calculator, as illustrated, this disk 4| being shown as rotatably mounted on an eyelet or grommet 42 secured to the body sheet Ill and backing sheet 38 and as having its lower edge projecting below the body sheet l0 so that it can be readily turned by hand. This disk 4| is shown as having a plurality of circular scales 45, 46, 47, 45a, 46a and 41a which are visible through six windows 48, 49, 50, 5|, 52 and 53 provided in the body sheet l0, these windows being provided in two series in three, one series being arranged in vertical alignment above the grommet 42 and the other series being arranged in vertical alignment below the grommet 42.

In the modified form of the invention shown in Fig. 8 a pair of slides is employed instead of the combination of a slide calculator and a rotary disk calculator as in the form of the invention shown in Figs. 1-7.

In this form of the invention a large slide |5a is secured to the body sheet Illa in the same manner as with the slide l5 illustrated in the form of the invention shown in Figs. 1-7 and the same reference numerals have therefore been employed but distinguished by the suffix a. The second and smaller slide I5!) is likewise secured to the body sheet Illa in the same manner as with the slide I in the form of the invention shown in Figs. 1-7 and the same reference numerals have therefore been employed but distinguished by the suffix b. To provide compactness, the slide I5!) is shown as interposed between the slide I5a and the body sheet, each of these slides being freely moved up and down by manipulation of their respective fingerpieces Ill) and Na in the same manner as with the slide I5 in the form of the invention illustrated in Figs. 1-7. It will be understood that the slides and the body sheet of the form of the invention shown in Figs. 8 and 9 are provided with numerical scales to permit of their use as calculators for any suitable purpose and that the slides I5a and I5b can be used either independently or conjointly for this purpose.

In the form of the invention illustrated in Fig. III, the slide I5c is arranged against the rear face of the body sheet I00 but has its lower end projecting through an opening 60 in the body sheet. The indicia (not shown) imprinted on the slide I is visible through openings 28c and 360 in the same manner as through the windows 28 and 36 in the form of the invention illustrated in Figs. 17. The opening is formed to provide a lower horizontal edge 6!, vertical straight edges 62 and an upper semi-circular edge 63 formed by a rounding extension 64 projecting downwardly into the openings 60. The vertical side edges 190 of the slide I50 bear against and are guided by the side straight edges 62 of the slot 60 in the same manner as with the straight edges 2I of the form of the invention illustrated in Figs. 1-7, this extended bearing surface for the slide I50 preventing the slide from sawing itself sidewise from the opening 60. In order to limit the upward movement of the slide I50, the lower end of the slide is rounded and this rounded lower end of the slide is folded to provide a forwardly projecting central tab 65 adapted to be grasped by the fingers of the operator. This tab 65 permits the slide to be conveniently worked up and down and at the same time engages the edge 63 of the opening 60 to limit the upward or inward movement of the slide I50. The engagement of the tab 65 and the edge 63 of the depending extension 64 occurs before the side edges I90 of the slide I 5c are disengaged from the bearing straight edges 62 of the opening 60 so that the slide is always held in proper bearing engagement with these bearing edges. The upper end of the slide I5c is supported in slots 20 in the same manner as with the form of the invention shown in Figs. 1-7.

In all of the forms of the invention it will be seen that the calculating slides can readily be moved up or down by manipulation of their tabs 0r fingerpieces and that the cooperating indicia printed on these slides and the body sheet can be set as the calculations may require, the desired figures to be determined being readable through the respective windows provided in the body sheet.

From the foregoing it will be seen that the present invention provides a very simple slide calculator made of sheet material which can be produced at very low cost and can be readily manipulated to give the exact information desired and further that the slides can be moved without undue friction and without danger of their sawing sidewise through the body sheet so as to bring the indicia of the slides out of register with the windows in the body sheet. It will further be seen that the slide is adequately protected and that the calculator as a whole will stand up under conditions of severe and constant use as in gasolene filling stations without gettingv out of order and requiring replacement.

I claim as my invention:

1. A calculator of the character described, comprising a cardboard body of sheet material. a slide of sheet material arranged against one face of said body and provided with a pair of opposite straight edges, and means for guiding said slide to move along a straight path and providing lateral bearing means of substantial extent for said slide and holding said slide against said one face of said body, comprising a pair of elongated cutouts formed in said body and each formed at its outside to provide a straight edge arranged parallel with and adjacent to the corresponding straight edge of said slide and a pair of tabs formed in said body and each projecting inwardly across one of said cutouts and engaging the outer face of said slide, said tabs being arranged at the centers of said cutouts and being substantially shorter than the length of said cutouts and holding said straight edges of said body in laterally displaced relation to said one face of said body to permit bearing engagement between said laterally displaced straight edges of said body and said opposite straight edges of said slide.

2. A calculator of the character described, comprising a cardboard body of sheet material, a cardboard slide of sheet material arranged against the rear face of said body and provided with opposite straight edges, and means for guiding said slide to move along a straight path and providing lateral bearing means of substantia1 extent for said slide and holding said slide against the rear face of said body comprising a pair of elongated cutouts formed in said body, and each formed at its outside to provide a straight edge arranged parallel with and adjacent to the corresponding straight edge of said slide and a pair of tabs formed in said body and each projecting inwardly across one of said cutouts and engaging the rear face of said slide, said tabs being arranged at the centers of said cutouts and being substantially shorter than the length of said cutouts and holding said straight edges of said body in rearwardly displaced relation thereto to permit bearing engagement between said rearwardly displaced straight edges of said body and said opposite straight edges of said slide.

3. A. calculator of the character described, comprising a cardboard body of sheet material, a large cardboard slide of sheet material arranged against the rear face of said body and provided with opposite straight edges, means for guiding said slide to move along a straight path and providing lateral bearing means of substantial extent for said slide and holding said slide against the rear face of said body comprising a pair of elongated cutouts formed in said body and each formed at its outside to provide a straight edge arranged parallel with and adjacent to the corresponding straight edge of said slide, and a pair of tabs formed in said body and each projecting inwardly across one of said cutouts and engaging the rear face of said slide, said tabs being arranged at the centers of said cutouts and being substantially shorter than the length of said cutouts and holding said straight edges of said body in rearwardly displaced relation to the rear face of said body to permit bearing engagement between said rearwardly displaced straight edges of said body and said oposite straight edges of said slide, a second small cardboard slide of sheet material interposed between said body and said large slide and provided with opposite straight edges, and means for guiding said second slide to move along a straight path and providing lateral bearing means of substantial extent for said second slide and holding said second slide against the rear face of said body comprising a second pair of elongated cutouts formed in said body and each formed at its outside to provide a straight edge arranged parallel with and adjacent to the corresponding straight edge of said second slide and a second pair of tabs formed in said body and each projecting inwardly across one of said second cutouts and engaging the rear face of said second slide, said second pair of tabs being each arranged at the center of the corresponding second cutout and being substantially shorter than the length thereof and holding said straight edges of said second pair of cutouts in rearwardly displaced relation to the rear face of said body to permit bearing engagement between said rearwardly displaced edges of said second pair of cutouts and said opposite straight edges of said second slide.

EMORY S. RUSSELL. 

